docs: def _add_mgmt_to_domains(self, conf, mgmts):
          """
          Add management network key('mgmt_net') to each domain. Note this
          assumes ``conf`` was validated.
  
          Args:
              conf(dict): spec
              mgmts(list): list of management networks names
  
          """
  
          for dom_name, dom_spec in conf['domains'].iteritems():
              domain_mgmt = [
                  nic['net'] for nic in dom_spec['nics'] if nic['net'] in mgmts
              ].pop()
  
              dom_spec['mgmt_net'] = domain_mgmt